Nicole “Snooki” Polizzi is giving ad vice to other celebrities on how to handle “tough” questions from David Letterman. She told Beth Ostrosky that the late-night host’s show was “no big deal.” The “Jersey Shore” cast and Ostrosky filmed segments for “Extra” on the rooftop of Hudson Terrace yesterday.

Snooki, who was Letterman’s guest a few nights ago, “claimed she wasn’t nervous at all, in fact brushing it off like it was no big deal,” said our spy. “Beth, on the other hand, said she was nervous” on the show last May and “asked Snooki for advice. Snooki just shrug ged and said, ‘It ain’t no thing!’ “